Search results for ""Society of Exploration Geophysicists""

Geoscientists and engineers are very comfortable using seismic data sets acquired with geophones, hydrophones, and accelerometers because we have a long, well-defined set of standards for acquiring, processing, and interpreting them. However, distributed acoustic sensing (DAS) seismic measurements are rapidly augmenting, and in some cases replacing, the data from these conventional tools. Technologists are frequently unaccustomed to using DAS seismic data sets since it directly acquires relative strain or strain rate measurements and not the more familiar pressure, displacement, velocity, and acceleration data. There are also acquisition parameter selections that must be made to optimize the acquired data to accomplish the purpose of the seismic survey. This book is designed to build an intuition and understanding of the value, limitations, and applications of DAS seismic technology.

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From Bohr magneton at the atomic level to van Allen belts in the magnetosphere around the Earth, from an absolute atomic gravimeter to the gravity field curvature, and from Bayesian stochastic inversion to artificial intelligence (AI), this Dictionary contains more than 3,200 entries and presents a terminology-guided summary of the gravity and magnetic theory, measuring instruments, methods of data acquisition, processing, analysis, and interpretation for geophysical studies of the Earth and other planets. Terrestrial applications include engineering (karst and faults), geodesy, geothermal, groundwater, volcano and global tectonic studies, CO2 sequestration and reservoir monitoring, as well as exploration for oil and gas, rare earth elements (REE), iron, gold, and other mineral resources. The terms are extensively cross referenced to other terms in the book. A comprehensive but concise list of referenced also is included.

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Useful attributes capture and quantify key components of the seismic amplitude and texture for subsequent integration with well log, microseismic, and production data through either interactive visualization or machine learning. Although both approaches can accelerate and facilitate the interpretation process, they can by no means replace the interpreter. Interpreter “grayware” includes the incorporation and validation of depositional, diagenetic, and tectonic deformation models, the integration of rock physics systematics, and the recognition of unanticipated opportunities and hazards. This book is written to accompany and complement the 2018 SEG Distinguished Instructor Short Course that provides a rapid overview of how 3D seismic attributes provide a framework for data integration over the life of the oil and gas field. Key concepts are illustrated by example, showing modern workflows based on interactive interpretation and display as well as those aided by machine learning.

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Fluids in the pore space of rocks causes attenuation and dispersion by the mechanism broadly known as wave-induced fluid flow. Of particular interest to exploration geophysics is inelastic attenuation and dispersion of body waves (P- and S-waves). Understanding fluid-related dissipation in hydrocarbon reservoir rocks, combined with improved measurements of attenuation and/or dispersion from recorded seismic data, may be used to estimate the hydraulic properties of these rocks. Discussing macroscopic, mesoscopic, and local flow and including theoretical models and experimental evidence, this book presents a systematic treatment of attenuation and dispersion mechanisms relevant to seismic, sonic, and ultrasonic wave propagation.

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Written for practicing geophysicists, Land Seismic Case Studies for Near-Surface Modeling and Subsurface Imaging is a comprehensive guide to understanding and analyzing seismic data. The culmination of land seismic data acquisition and processing projects conducted by the author over the last two decades, this book contains nearly 800 figures from worldwide case studies—conducted in both 2D and 3D. Beginning with Chapter 1 on seismic characterization of the near-surface, Chapter 2 presents near-surface modeling by traveltime and full-wave inversion, Chapter 3 presents near-surface modeling by imaging, and then Chapter 4 includes detailed case studies for near-surface modeling. Chapter 5 reviews single- and multichannel signal processing of land seismic data with the key objective of removing surface waves and guided waves that are characterized as coherent linear noise. Uncommon seismic data acquisition methods, including large-offset acquisition in thrust belts to capture the large-amplitude supercritical reflections, swath-line acquisition, and joint PP and SH-SH seismic imaging are highlighted in Chapter 6, and Chapter 7 presents image-based rms velocity estimation and discusses the problem of velocity uncertainty. The final two chapters focus exclusively on case studies: 2D in Chapter 8 and 3D in Chapter 9. An outstanding teaching tool, this book includes analysis workflows containing processing steps designed to solve specific problems. Essential for anyone involved in acquisition, processing, and inversion of seismic data, this volume will become the definitive reference for understanding how the variables in seismic acquisition are directly reflected in the data.

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The scope of engineering seismology includes geotechnical site investigations for buildings and engineering infrastructures, such as dams, levees, bridges, and tunnels, landslide and active- fault investigations, seismic microzonation, and geophysical investigations of historic buildings. These projects require multidisciplinary participation by the geologist, geophysicist, and geotechnical and earthquake engineers. A key objective of this book (SEG Investigations in Geophysics Series No. 17) by Öz Yilmaz is to encourage the specialists from these disciplines to apply the seismic method to solve the many challenging engineering problems they face. The broader scope of engineering seismology also includes exploration of earth resources, including groundwater exploration, coal and mineral exploration, and geothermal exploration. While focusing on the application of the seismic method to geotechnical site investigations, this book includes many case studies in all of the applications of engineering seismology.

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This second volume provides a foundation for understanding the vigorous, relevant, and fascinating field of seismic processing, addressing that portion which precedes migration. Written for the non-expert, this second volume of the two-volume introductory text reveals the limitations and potential pitfalls of seismic data, prepares both seismic interpreters and acquisition specialists for working with seismic processing geophysicists, explains seismic processing operations as a series of solutions to problems, and demonstrates the dependence of a final interpretable seismic volume on its many seismic processing decisions.Although seismic processing is inherently mathematical, this text uses numerous illustrations and real data examples, providing an intuitive understanding of the seismic processing procedures and resorting to an algebra-based argument only on rare occasions. The first volume starts with migration. This second volume addresses pre-migration processing. In combination, these two volumes present seismic processing topics in order reverse of a typical processing sequence. Through this reverse ordering, the reader understands an algorithm's input requirements, providing motivation for understanding the preceding algorithm in the processing sequence.

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Over the past decade, microseismic monitoring, a technology used to evaluate the completions of wells drilled to produce hydrocarbons from unconventional reservoirs, has grown increasingly popular among oil and gas companies. Microseismic Monitoring, by Vladimir Grechka and Werner M. Heigl, presents a thorough description of how to process microseismic data and the underlying theory, of what can and cannot be inferred, and to what level of certainty. The layout of the book follows the passage of a seismic wave – from a source triggered by hydraulic stimulation, through hydrocarbon-bearing formations, towards motion sensors. The analysis of various approaches to harvesting the source-related information from microseismic records has singled out the accuracy of the velocity model as the most critical ingredient for the quality of microseismic deliverables and our understanding of the information contained in those. An accurate velocity model, fully accounting for the strong elastic anisotropy of hydraulically fractured shales, is a prerequisite for obtaining precise event hypocenters and interpretable seismic moment tensors. The ray theory complemented by its modern extensions, the paraxial ray tracing and Frechet ray tracing, provides the only practical means available today for building such models. This book was written for geophysicists interested in learning advanced microseismic data-processing techniques.

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Providing geophysicists with an in-depth understanding of the theoretical and applied background for the seismic diffraction method, Classical and Modern Diffraction Theory covers the history and foundations of the classical theory and the key elements of the modern diffraction theory. Chapters include an overview and a historical review of classical theory, a summary of the experimental results illustrating this theory, and key principles of the modern theory of diffraction; the early cornerstones of classical diffraction theory, starting from its inception in the 17th century and an extensive introduction to reprinted works of Grimaldi, Huygens, and Young; details of the classical theory of diffractions as developed in the 19th century and reprinted works of Fresnel, Green, Helmholtz, Kirchhoff, and Rayleigh; and the cornerstones of the modern theory including Keller’s geometrical theory of diffraction, boundary-layer theory, and super-resolution. Appendices on the Cornuspiral and Babinet’s principle also are included.

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In his classic text, Seismic Prospecting for Oil, C. Hewitt Dix remarks that the correlation of one reflection record with another, that is, the interpretation of seismic data, is a procedure that “can hardly be described in words.” First Steps in Seismic Interpretation (Geophysical Monograph Series No. 16) is a book about fundamental concepts and practices of seismic interpretation that attempts to achieve such a description. Intended for beginning interpreters, this book approaches interpretation via synthesis of concepts and practical applications rather than through formal treatment of basic physics and geology. It is based on the author’s personal experience as a seismic interpreter and is organized along the lines of notes from interpretation classes that he designs and teaches.

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Elementary, conceptual, and easy to read, this book describes the methods and techniques used to estimate rock properties from seismic data, based on a sound understanding of the elastic properties of materials and rocks and how the amplitudes of seismic reflections change with those properties. By examining the recorded seismic amplitudes in some detail, we can deduce properties beyond the basic geological structure of the subsurface. We can, using AVO and other amplitude techniques, characterize rocks and the reservoirs inside them with some degree of qualitative, and even quantitative, detail. Mathematics is not ignored, but is kept to a minimum. Intended for geophysicists, seismic acquisition specialists, processors, and interpreters, even those with little previous exposure to "quantitative interpretation", "interpretive processing", or "advanced seismic analysis", this book also would be appropriate for geologists, engineers, and technicians who are familiar with the concepts but need a methodical review as well as managers and businesspeople who would like to obtain an understanding of these concepts.

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Filling the gap between theoretical literature and the routine activities of geophysicists in the oil industry, The Seismic Signal and Its Meaning is a translation of the second edition of Análise do Sinal Sísmico, published in Portuguese by Sociedade Brasileira de Geofísica (SBGf). For those performing acquisition, processing, and/or interpretation, this book will aid an understanding of how practical problems may have important links to seismic data analysis theory. With an emphasis on providing an objective description of the physical and mathematical aspects that support these links, the rules necessary for robust reservoir characterization are presented. With an extensive development of Gassmann’s (and Biot) theory and its relevance, the book concentrates on phase and amplitude distortions to the seismic signal, the physical processes that it undergoes, and the interpretation methods to recover rock physics properties. Capturing 30 years of teaching and improvement as a part of Petrobras internal courses, the book is a modern treatment, reflecting the many advances that have occurred in geophysics. The book serves as both a text and a reference.

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This first of two volumes presents mathematical and physical foundations common to all EM methods and has chapters on numerical and analog modeling. The chapters on electrical properties of rocks and resistivity characteristics of geologic targets help readers envisage different kinds of ground structures that may be addressed and the effect of various factors on observed conductivities of rocks. Basic principles of modern instrument design are discussed in the chapter on detection of repetitive EM signals. The last chapter discusses the principles of EM inversion as a first step toward achieving the elusive goal of automatic interpretation of EM data.

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